JP2516592B2 - On-line roll grinding method for rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to an improvement of an on-line roll grinding method for a rolling mill.

<Prior Art> In hot rolling mills and the like, various online roll grinding methods for grinding a roll surface into a required profile during rolling have been put into practical use in order to improve productivity and quality of rolled material. is there. This method generally grinds the surface of a roll into a required profile by pressing a plurality of grinding bodies such as grindstones on the surface of a rotating work roll at an arbitrary set pressure and reciprocating in parallel to the roll axis. To do.

A conventional online grinding device will be described with reference to FIG.

In the figure, 1 is a work roll, 2 is a rolling mill housing, 3
Indicates a plurality of grinding bodies (grinding stones in the example), the grinding stone 3 is attached to the tip of the grinding stone holder 4, the rear part of each grinding stone holder 4 is connected to the piston 5, and the piston 5 is a cylinder built in the frame 6. 7, the grindstones 3 are individually pressed onto the surface of the roll 1 by supplying the pressure liquid 8 to the piston head side. Further, the frame 6 is supported on a mount 9 provided in the housing 2, and the frame 6 can reciprocate along a guide 9a on the mount 9 via a cylinder 10 in parallel with the roll axis.

Therefore, when grinding the roll 1 online, a state in which the hydraulic pressure 8 of an arbitrary set pressure is supplied to the head side of the piston 5 of each grindstone holder 4 by a hydraulic pressure adjusting valve (not shown) and the grindstone 3 is pressed against the roll surface The grinding can be performed by operating the cylinder 10 to reciprocate the three groups of grindstones.

<Problems to be Solved by the Invention> However, in the above-described apparatus, the grindstone holder 4 is not supported during grinding.
Since the grindstone 3 is constantly pressed against the surface of the roll 1 with a constant hydraulic pressure, the grindstone 3 moves forward with respect to the roll axis when, for example, grinding the crowning portion or step wear portion of the roll 1 into a required profile. In some cases and in other cases, the sliding friction resistance force ΔP is generated between the grindstone holder 4 and the cylinder 7. For this reason, there is a problem that the pressing force of the grinding surface of the grindstone 3 is not constant and it becomes difficult to grind the required profile with high accuracy. This will be described more specifically with reference to FIG.

Fig. 5 shows the crowning parts at both ends of the work roll 1.
FIG. 6 is a plan view exaggeratingly showing a grinding state when grinding C ₁ and C ₂ . First, when the group of grindstones 3 is moved by the maximum stroke S toward the arrow a side for grinding, the grindstone 3a on the left side in the figure moves to the position 3a 'while retreating due to the inclination α of the crowning portion C ₁ . The pressing force on the piston head side by the hydraulic pressure of the grindstone holder 4 at this time is P, the sliding frictional resistance between the grindstone holder 4 and the cylinder 7 (see FIG. 4), that is, the piston 5 of the grindstone holder 4 (see FIG. 4). If the sliding frictional resistance force generated between the cylinder 7 and the cylinder 7 is ΔP ₁ , the grindstone holder 4 retracts toward the frame 6 side at the same time when the grindstone 3a starts traversing (arrow a).
The crimping force Pc ₁ of the crowning part C ₁ becomes P + ΔP ₁ and the grinding stone 3
a flat portion pressing force P _F of the flat portion F retraction is stopped for reaching the grinding wheel 3a to F is _{P F = P C0 = P <} Pc 1 next to the roll 1, the grinding amount Delta] t ₁ of the crowning portion C ₁ is It becomes larger than the grinding amount Δt ₂ of the flat portion F. On the other hand, as for the grindstone 3b on the right side in the figure, the pressing force P _F is P-ΔP in the flat portion F as in the above, but the grindstone 3b is rolled by the roll 1 in the crowning portion C ₂ because of the downward gradient α.
Traverse to the 3b 'position while advancing to the side. If the sliding frictional resistance force between the grindstone holder 4 and the cylinder 7 at this time is ΔP ₂ , the pressure force P _C2 of the ground surface at the crowning portion C ₂ is P _C2 = P
−ΔP ₂ . Since ΔP ₂ is sufficiently smaller than ΔP _{1 due} to the structure of the equipment, Pc ₂ = P if ΔP ₂ = 0. In this case, the flat portion F and the crowning portion C ₂ have substantially the same amount of grinding and are Δt ₂ . Return stroke of grindstone 3 (direction of arrow b)
Then, the grinding amount of the grindstones 3a and 3b is opposite to the above case. Therefore, the total amount of grinding of the surface of the roll 1 by one reciprocation of the grindstones 3a, 3b (that is, an even number of strokes) is Δt ₁ + Δt _{2 for} both the left and right crowning portions C ₁ and C ₂ , but is the same, but in the flat section F It becomes 2Δt ₂ , which is smaller than the crowning parts C ₁ and C ₂ .

The above is grinding with an even number of strokes, but if grinding is further carried out in the direction of arrow a, the total grinding amount will be the crowning part C ₁ = 2Δt ₁ + Δt ₂ > crowning part
C ₂ section = Δt + 2Δt ₂ > flat portion F = 3Δt ₂ . In order to cancel the sliding frictional resistance force ΔP ₁ when the grindstone holder 4 retracts, hydraulic pressure may be applied to the rod side of the piston 5, but this method makes the hydraulic pressure control system extremely complicated and costly. However, there are many problems in practical use due to the installation of the forward / backward movement amount detection sensor of the grindstone holder 4 and its responsiveness.

The present invention has been proposed in view of the above situation, the pressing force of the grinding surface of the grindstone is made uniform with the forward or backward stroke of the grindstone regardless of the profile of the roll surface, and the grinding amount in each stroke is An object of the present invention is to provide an on-line grinding method for a rolling mill that can be made uniform at all times, thereby enabling highly accurate grinding of a required profile.

<Means for Solving the Problems> The method of the present invention for achieving the above-mentioned object has a pressing function capable of pressing a grinding body at the tip and pressing the grinding body to the roll surface at an arbitrary set pressure. An on-line roll grinding apparatus for a rolling mill comprising a grinding body holder connected to a rear portion, a frame that houses a plurality of the grinding body holders in a roll axis direction, and a frame drive mechanism that reciprocates the frames in the roll axis direction. When the roll is ground by the grinding body, the reciprocating direction of the grinding body in the roll axis direction is inclined with respect to the roll line within a plane including the roll axis.

<Embodiment> FIG. 1 is a plan view of a grinding apparatus for carrying out an embodiment of the method of the present invention. The same or similar members as those shown in FIG. The description will be omitted.
Compared to the device shown in FIG. 4, the illustrated device guides the frame 6 and the frame 6 such that the reciprocating direction of the group of 3 grinding wheels forms an arbitrary set angle θ with respect to the roll axis OR in a plane including the roll axis OR. The center line OG of 9a is supported on the mount 9,
The configuration of each member other than that is the same as that of the apparatus shown in FIG. Here, the roll axis of the center line OG of the guide 9a
The magnitude of the tilt angle θ with respect to OR will be described below. That is, the roll axis of the stepped portion S due to wear of the work roll 1
Tilt angle αa for OR or crowning portion C (Fig. 3 b refer) alpha _amax of inclination αb relative roll axis OR of,, alpha suitably large set of tilt θ of the guide 9a than _bmax.

A method of grinding using the apparatus having the above configuration will be described with reference to FIG.

When the frame 6 is ground by moving the frame 6 in the direction of arrow a, that is, in the direction approaching the roll axis OR, the inclination angle θ of the grindstones 3a, 3b at both ends of the work roll 1 is the same as that of the crowning portion C _{2 on} the right side in the figure. Since it is larger than the inclination angle α with respect to the roll axis OR, the grindstones 3a, 3b, that is, the grindstone holder 4 in each grinding section of the work roll 1 is constantly retracted toward the frame 6 side, and a constant pressure force Pc ₁ = P _F = Pc ₂ = Grind with P _O + ΔP ₁ . That is, the sliding frictional resistance force ΔP between the piston 5 and the cylinder 7 is increased by increasing the inclination angle θ of the crowning portion C ₂ with respect to the roll axis OR, so that the crowning portion C ₁ , the flat portion F, and the crowning portion C ₂ are respectively separated. Although the angle with respect to the guide 9a is different, the sliding friction resistance ΔP is the same even if the angle of each section is changed, and Pc ₁ = P _F = Pc ₂ = P _O + ΔP ₁
Becomes Therefore, the grinding force of each grindstone group 3 is also uniform at Δt ₁ . Next, when the frame 6 is moved to the arrow b side, the grindstones 3a and 3b grind while advancing toward the roll axis OR side in each grinding section, so that the pressure bonding force Pc ₁ = P _F = Pc ₂ = P _O −ΔP Although the _2, since it is assumed that P ₂ = 0, the grinding amount is uniform and Delta] t _2.

Therefore, regardless of whether the number of reciprocating grinding strokes is an even number or an odd number, the cumulative amount of grinding is always made uniform in each part along the profile of the roll surface. Further, by increasing / decreasing the piston head side pressing force P by an amount corresponding to the piston sliding frictional resistance force ΔP according to the reciprocating grinding stroke in the roll axis direction, the pressure force of the grindstone 3 can be made constant at all times, and the grinding amount Δt. Can be made constant with the reciprocating stroke, and more stable grinding is possible.

In the illustrated apparatus, the grindstone 3 is mounted on the frame 6 so as to be able to move back and forth in a direction perpendicular to the axis OR of the work roll 1, but the grindstone 3 is in the roll axial direction with respect to the normal line of the surface of the work roll 1. It may be mounted so as to be able to move forward and backward in a direction forming an arbitrary inclination angle. The reciprocating inclination angle θ of the grindstone 3 may be opposite.

The above assumes P ₂ = 0 to simplify the discussion,
Of course, the same logic holds even if ΔP ₂ ≠ 0.

<Advantages of the Invention> According to the present invention, the direction of reciprocal movement in the axial direction of the grindstone roll is tilted with respect to the roll axis within a plane including the roll axis, and the tilt angle is set to be larger than the maximum tilt angle with respect to the roll axis of the roll profile. Therefore, when the grindstone holder moves backward in the frame direction, the crimping force Pa on the grinding surface of the grindstone is P + ΔP ₁ , and conversely, when it is the stroke away from the frame, the crimping force Pb is P-.
Since there is a relationship of ΔP ₂ , it is possible to grind with a uniform crimping force in both reciprocating strokes. Further, by increasing or decreasing the pressing force on the piston head side by ΔP according to the reciprocating grinding stroke in the roll axis direction, the crimping forces Pa and Pb can be made constant at all times, and the grinding amount becomes constant with the reciprocating stroke. More stable grinding is possible. As a result, it is possible to always grind the required roll profile with high accuracy by extremely simple control means.

[Brief description of drawings]

FIG. 1 is a plan view of a grinding apparatus for carrying out a method of an embodiment of the present invention, FIG. 2 is a drawing for explaining its grinding action, and FIG. 3 (a) shows a reciprocating direction of a grindstone corresponding to a step portion. Conceptual diagram, FIG. 3 (b) is a conceptual diagram showing the reciprocating direction of the grindstone corresponding to the crowning portion, and FIG. 4 is a conceptual diagram of a conventional grinding device,
FIG. 5 is an explanatory view of the grinding action. In the drawings, 1 is a work roll, 3 is a grindstone, 4 is a grindstone holder, 6 is a frame, 10 is a cylinder, OR is a roll axis, and θ is a tilt angle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunio Yamamoto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City Sanryo Heavy Industries Ltd. Hiroshima Factory (72) Inventor Kanji Hayashi 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City Sanryo Heavy Industries Co., Ltd. Hiroshima Works (72) Inventor Tatemoto Tanimoto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima Sanryo Heavy Industries Co., Ltd. Hiroshima Works (56) Reference JP-A-61-253106 A)

Claims (1)

(57) [Claims] 1. A grinding body holder in which a grinding body is mounted on a tip portion and a pressing mechanism for pressing the grinding body on a roll surface at an arbitrary set pressure is connected to a rear portion, and the grinding body holder is a roll shaft. In an online roll grinding device of a rolling mill, which comprises a frame for accommodating a plurality of frames in a predetermined direction and a frame drive mechanism for reciprocating the frame in the roll axis direction, in grinding the roll with the grinding body, in the roll axis direction of the grinding body. An on-line grinding method for a rolling mill, which comprises tilting the reciprocating motion of the above-mentioned direction within a plane including the roll axis with respect to the roll axis.